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BEESWAX
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the nitrate evaporated and the residue employed for the detection of resin
by means of acetic anhydride and sulphuric acid (see General Methods, 20).
The. quantitative determination may be effected by Twitchell's method
(see General Methods, 20).
8. Paraffin Wax and Ceresine.—As a preliminary test, 5 grams of
the wax, about 25 c.c. of semmormal alcoholic potassium hydroxide and 20 c.c. of 95% alcohol are boiled for an hour in a reflux apparatus over a naked flame : with pure wax the solution is clear, or almost clear, and remains so when diluted with hot water, but with wax mixed with paraffin wax or ceresine, the liquid remains turbid, and becomes still more so when diluted with water.1
A more certain and even quantitative test may be made by Leys'
method2: 10 grams of the wax, 25 c.c. of alcoholic potash. (45 grams KOH per litre of absolute alcohol) and 50 c.c. of pure benzene are boiled for 20 minutes in a reflux apparatus on an asbestos card over a naked flame, 50 c.c. of water being then added and the boiling continued, for 10 minutes. After a short rest, the liquid separates into two layers : an upper, clear, yellowish one (benzene solution of higher alcohols and hydrocarbons) and a lower, somewhat opalescent one (aqueous-alcoholic soap solution). As soon as the separation is sharp, the lower hot liquid is drawn off and replaced by 50 c.c. of hot water, and the liquid boiled for 10 minutes with a reflux apparatus. The aqueous solution is then immediately withdrawn and the benzenic liquid transferred to a tared capsule, the various vessels in which the operations have been conducted being washed out with hot benzene3; the solvent is then evaporated on the water-bath and the residue dried at 100° and weighed. This gives the total weight of higher alcohols and hydrocarbons contained in .the wax and from this the content of extrane- ous hydrocarbons may be deduced, knowing that in pure wax the sum of alcohols and hydrocarbons never exceeds 55% (usually oscillating about 50%).
If desired, the hydrocarbons may, according to Leys, be separated
quantitatively from the higher alcohols by means of a mixture of amyl alcohol and cone, hydrochloric acid, in which the latter dissolve (see original paper) ; or, as Buchner recommends,* the acetyl number (sea General Methods, u) of the mixed higher alcohols and hydrocarbons may be deter- mined and the quantity of the former deduced by taking 122 as the mean acetyl number of the higher alcohols of the pure wax.
9. Test for Carnauba Wax and Insect or Chinese Wax.—No
special reactions exist for identifying these waxes in beeswax ; when, how- ever, the presence of other extraneous substances has been excluded and any stearic acid and resin eliminated as indicated above (6), their presence may be presumed from increase of the specific gravity, melting point,
1 Werder : Monit. scient., igoi, p. 127.
2 Journ. de Pharm. et Chim., 1912, V, p. 577.
3 Very suitable for this purpose is a special vessel (Boule a decantation chaude)
devised by Leys and consisting of a tapped funnel flattened on one side so that it may be heated like an ordinary flask.
* Zsitschr, f. offentl. Chem., 1913, p. 447.
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